How To Fix FITP128 - Communication error: RFC destination &1 cannot be called

SAP Error Message - Details

• Message type: E = Error

• Message class: FITP -

• Message number: 128

• Message text: Communication error: RFC destination &1 cannot be called

What causes this issue?

The program you are using needs to communicate with an external program
in order to access the data in the external reservation system. However,
the communications interface is not available at the moment.,,

System Response

The system has determined that communication with the external
reservation system has been interrupted.

How to fix this error?

Contact your system administrator.

Procedure for System Administrators

Communication with the external reservation system takes place across an
external gateway. Use Transaction SM59 to test the RFC destination
<ZH>&v1&</><ZH></> (under TCP/IP Connections). This call was not
successful in the application program and resulted in the error
<ZH><ZH>&V2&</></><ZH><ZH> &V3& </></>
The connection will only work in the application program once the test
using SM59 has been completed successfully without errors. In
particular, the program must be registered with the gateway.
In certain situations (particularly in a test environment), it may be
necessary to communicate with the current or another reservation system
using a different RFC destination. To do this, you must make settings in
Customizing under Financial Accounting -> Travel Management -> Travel
Planning -> Master Data -> Technical Control Parameters for Travel
Planning. For further information, see the documentation for that
activity and the documentation for Technical and Organizational
Prerequisites.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message FITP128 - Communication error: RFC destination &1 cannot be called ?

  The SAP error message FITP128 indicates a communication error with a Remote Function Call (RFC) destination. This error typically occurs when the system is unable to establish a connection to the specified RFC destination. Here are the potential causes, solutions, and related information for this error:
  Causes:
  
  Incorrect RFC Destination Configuration: The RFC destination may not be configured correctly in the SAP system.
  Network Issues: There may be network connectivity issues between the SAP system and the target system.
  Target System Down: The target system that the RFC destination points to may be down or not reachable.
  Authorization Issues: The user credentials used for the RFC connection may not have the necessary authorizations.
  Firewall Restrictions: Firewalls or security settings may be blocking the communication between the systems.
  SAP Gateway Issues: The SAP Gateway service may not be running or may be misconfigured.
  
  Solutions:
  
  
  Check RFC Destination Configuration:
  
  Go to transaction SM59 in the SAP GUI.
  Locate the RFC destination that is causing the error and check its configuration.
  Ensure that the connection type, target host, and system number are correct.
  
  
  
  Test the Connection:
  
  In transaction SM59, select the RFC destination and use the "Connection Test" option to verify if the connection can be established.
  
  
  
  Check Network Connectivity:
  
  Use tools like ping or telnet to check if the target system is reachable from the SAP system.
  Ensure that there are no network issues or outages.
  
  
  
  Verify Target System Status:
  
  Ensure that the target SAP system is up and running and that the necessary services are active.
  
  
  
  Check User Authorizations:
  
  Verify that the user credentials used for the RFC connection have the necessary authorizations to access the target system.
  
  
  
  Review Firewall Settings:
  
  Check if there are any firewall rules that might be blocking the communication between the two systems.
  
  
  
  Check SAP Gateway:
  
  Ensure that the SAP Gateway service is running on both the source and target systems.
  You can check the status of the gateway using transaction SMGW.
  
  
  
  Review Logs:
  
  Check the system logs (transaction SM21) and the developer trace files (transaction ST11) for any additional error messages that might provide more context.
  
  
  
  Related Information:
  
  RFC Types: Understand the different types of RFC connections (e.g., T, 3, and M) and their configurations.
  SAP Notes: Search for relevant SAP Notes in the SAP Support Portal that may address specific issues related to RFC communication errors.
  Documentation: Review SAP documentation for detailed information on configuring and troubleshooting RFC destinations.
  
  By following these steps, you should be able to identify and resolve the cause of the FITP128 communication error.